Microlithography illumination systems, components and methods

ABSTRACT

The disclosure relates to microlithography systems, such as EUV microlithography illumination systems, as well as related components, systems and methods.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119 to German patentapplication serial number 10 2006 060 101.7, filed Dec. 18, 2006, whichis hereby incorporated by reference.

FIELD

The disclosure relates to microlithography systems, such as EUVmicrolithography illumination systems, as well as related components,systems and methods.

BACKGROUND

Projection exposure apparatuses for use in microlithography are known.

SUMMARY

The disclosure relates to microlithography systems, such as EUVmicrolithography illumination systems, as well as related components,systems and methods.

In one aspect, the disclosure provides an EUV microlithographyillumination system. The system includes an illumination optics designedso that, during use, the illumination optics can guide light from aradiation source to an object field in an object plane. The system alsoincludes an illumination-angle sensor element designed so that, duringuse, the illumination-angle sensor can determine an actualillumination-angle distribution of a projection exposure apparatus in afield plane of the illumination optics. The system further includes anillumination-angle evaluation device including a signal connection tothe illumination-angle sensor element, the illumination-angle evaluationdevice being designed so that, during use, a nominal illumination-angledistribution is stored via the illumination-angle evaluation device. Inaddition, the system includes an illumination-angle control deviceincluding a signal connection to the illumination-angle evaluationdevice, the illumination-angle control device being designed so that,during use, the illumination-angle control device generates anillumination-angle control signal depending on a difference between theactual illumination-angle distribution and the nominalillumination-angle distribution. The system also includes at least onemovable illumination-angle diaphragm device including a signalconnection to the illumination-angle control device, the at least onemovable illumination-angle diaphragm device being configured so that,during use, the at least one illumination-angle diaphragm device canmove at least one illumination-angle diaphragm body to achieve anadjustable, partial attenuation of the light in the area of a pupilplane of the illumination optics.

In another aspect, the disclosure provides a projection exposureapparatus for EUV microlithography. The apparatus includes anillumination optics designed so that, during use, the illuminationoptics can guide light from a radiation source to an object field in anobject plane. The apparatus also includes a projection optics designedso that, during use, the projection optics can image the object fieldinto an image field in an image plane. The apparatus further includes afield-distribution sensor element designed so that, during use, thefield-distribution sensor element can determine an actual intensitydistribution of the projection exposure apparatus in a field plane ofthe projection optics. In addition, the apparatus include afield-distribution evaluation device including a signal connection tothe field-distribution sensor element, the field-distribution evaluationdevice being designed so that, during use, a nominal distribution ofintensity over the field can be stored via the field-distributionevaluation device stored. The apparatus also includes afield-distribution control device including a signal connection to thefield-distribution evaluation device, the field-distribution controldevice designed so that, during use, the field-distribution controldevice generates a signal depending on the difference between the actualintensity distribution and the nominal intensity distribution. Theapparatus further includes at least one movable field-distributiondiaphragm device including a signal connection to the field-distributioncontrol device, the at least one movable field-distribution diaphragmdevice designed so that, during use, depending on the field-distributioncontrol signal, at least one movable field-distribution diaphragm devicemoves at least one field-distribution diaphragm body to achieve anadjustable, partial attenuation of illumination light of the radiationsource in the area of a field plane of the illumination optics.

In a further aspect, the disclosure provides a method that correcting anillumination parameter of an EUV microlithography projection exposureapparatus.

In an additional aspect, the disclosure provides a method that using aprojection exposure apparatus according to project at least part of amask onto an area of a photo-sensitive material (e.g., to make amicrostructured device).

In some embodiments, the disclosure provides an illumination systemdesigned so that illumination parameters, such as the ellipticity of theillumination-angle distribution, correspond more closely to desiredvalues.

EUV (extreme ultraviolet) refers to a wavelength range, such as between10 and 30 nm.

In some embodiments, the disclosure provides an illumination system forEUV microlithography including

-   -   an illumination optics for guiding illumination light of a        radiation source to an object field in an object plane;    -   an illumination-angle sensor element for determining an actual        illumination-angle distribution of a projection exposure        apparatus in a field plane of the illumination optics;    -   an illumination-angle evaluation device which is provided with a        signal connection to the illumination-angle sensor element and        in which a nominal illumination-angle distribution is stored;    -   an illumination-angle control device which is provided with a        signal connection to the illumination-angle evaluation device        and, depending on the difference between the actual        illumination-angle distribution and the nominal        illumination-angle distribution, generates an illumination-angle        control signal;    -   and at least one movable illumination-angle diaphragm device        which is provided with a signal connection to the        illumination-angle control device and moves at least one        illumination-angle diaphragm body to achieve an adjustable,        partial attenuation of the illumination light of the radiation        source in the area of a pupil plane of the illumination optics.

It was realized that the illumination-angle distribution in the objectplane of the illumination system can be evaluated or monitored via acorresponding measurement, thus allowing for an automatic compensationmechanism to both detect and correct alterations of theillumination-angle distribution originating from misadjustment, thermaldrifts or design effects. When putting the disclosure into practice,experiences from the UV microlithography with regard to diaphragmadjustment as a mechanism for changing the illumination angles may proveuseful. Corresponding UV projection exposure apparatuses are known fromDE 100 43 315 C1 and DE 10 2004 063 314 A1. Parameters characterizingthe illumination-angle distribution can be automatically kept withindefault limits via the illumination system according to the disclosure.This can substantially increase the service life of a projectionexposure apparatus, which is equipped with the illumination systemaccording to the disclosure, until it should be shut down formaintenance, for example. Correspondingly, an increased throughput ofthe projection exposure apparatus can be obtained. The movableillumination-angle diaphragm device may be designed as a correctiondiaphragm which is integrated into the illumination system according tothe disclosure in or adjacent to a pupil plane of a projection optics ofa projection exposure apparatus, or is disposed in a plane which isconjugated thereto and attenuates the illumination of an entrance pupilof the projection optics in a way that at least some source images inthe entrance pupil of the projection optics, which are associated withthe individual facets of the pupil facet mirror, are partially shadowedby one and the same diaphragm edge. The diaphragm edge of such acorrection diaphragm may be used to affect the illumination parameterstelecentricity and ellipticity. This can allow for the attenuation orshadowing of the pupil facet mirror to be adapted to different radiationsource geometries and different illumination settings. Attenuation via acorrection diaphragm may occur directly adjacent to the pupil facetmirror so that individual facets of the pupil facet mirror itself areshadowed. Alternatively, the correction diaphragm may be disposed in thearea of a pupil plane conjugated to the pupil facet mirror, i.e. notadjacent to the pupil facet mirror. In either case, either someindividual facets or some source images associated with these individualfacets are shadowed by one and the same diaphragm edge.

In certain embodiments, an illumination system may be provided with asensor element which is capable of detecting the illumination angledistribution over the entire field plane and may for example be realizedby inserting an output coupler by which the illumination-angle sensorelement is exposed to the illumination light. In some embodiments, thesensor element may be exposed to the illumination light via a beamsplitter. The illumination-angle sensor element which may be providedwith a sensor element which is capable of detecting the illuminationangle distribution over the entire field plane allows for completemonitoring of the illumination-angle distribution over the entire field.

In certain embodiments, an illumination system is provided with anillumination-angle sensor element which is capable of detecting theillumination-angle distribution in at least one field position by usingillumination light at the edge of the cross-section of the illuminationlight, this allows for the illumination-angle distribution to bemonitored during the projection operation of the illumination system.

An illumination-angle sensor element can include at least one deflectionelement for deflecting a detection beam path of the illumination-anglesensor element away from a main beam direction of the illuminationlight, e.g., by 90°, which can allow for a compact design of theillumination-angle sensor element.

An illumination-angle sensor element can detect the illumination-angledistribution by using illumination light at four edge positions of thebeam cross-section of the illumination light, the edge positionsdefining the corners of a rectangle, may be used for illumination lightto be obtained from areas where it is usually not, or only to a limitedextent, needed for projection. This ensures that the projection processcontinues while being monitored by the illumination-angle sensorelement.

An illumination-angle sensor element can be designed to detect theillumination angles and, at the same time, the integral of theillumination light arriving from all detected illumination angles mayadditionally be used as an energy/intensity sensor for monitoring thetotal performance of the radiation source.

An illumination-angle sensor element can include an apertured diaphragmat a position in a field plane, or a plane of the illuminated opticsconjugated thereto, which may be exposed to illumination light, and aspatial detector element disposed downstream of the apertured diaphragmfor detecting an intensity distribution which corresponds to theillumination-angle distribution at the site of the apertured diaphragmensures a high-precision measurement of the illumination-angledistribution whilst providing a simple design.

A spatial detector element can include a CCD array as the spatialdetector element can be provided with a conversion element convertingthe wavelength of the EUV illumination light into a wavelengthdetectable by the CCD array is very sensitive. A correspondingconversion element allows for the wavelength of the illumination lightto be converted into a wavelength which is detectable by the CCD array.A response, which may depend on the angle of incidence of theillumination light when hitting the conversion element, i.e. anintensity of the wavelength depending on this angle of incidence, thewavelength being generated by the conversion element and detectable bythe CCD array, can be determined prior to the actual illuminationparameter measurement via a calibration measurement and deducted fromthe actual measurement. An incidence-angle dependence of the response ofthe conversion element then does not falsify the measurement result ofthe spatial detector element.

A diaphragm device can be provided with a plurality of individualdiaphragm bodies which, starting from the edge, are insertable into anilluminated aperture of the pupil plane independently of each otherallows for a flexible adjustment of the illumination-angle distribution.

Diaphragm bodies of an illumination system of the aforementioned typehaving an edge contour which can lead in the direction of insertion andcan be adapted to an illumination substructure of the pupil plane to beshadowed allow for a defined shadowing to be obtained.

If, in an illumination system, the number of diaphragm bodies is adaptedto the illumination parameters to be corrected, unwanted hunting effectsduring the correaction of the illumination parameters may be avoided.If, for example, the ellipticity of the illumination-angle distributionis to be monitored and corrected in two orientations, the energy orintensity, respectively, of exposure should be adjusted in octantsobtained in the pupil plane. Correspondingly, it is advantageous in thiscase to use eight individual diaphragm bodies.

An insertion drive can cooperate with an individual diaphragm body andincludes a guide unit for guiding the insertion movement as well as apivotable lever arm which is articulated with a guide body which isguided in the guide unit and firmly connected to a base body of theindividual diaphragm body and cooperates with a pivot drive motorensures a high-precision insertion whilst providing a simple design. Insome embodiments, the insertion drive may also be realized via, forexample, a stepper motor.

A pivot drive motor can be configured as an electric motor in a way thata portion of the lever arm simultaneously forms a rotor of the electricmotor includes a particularly low number of components.

In some embodiments, a projection exposure apparatus for the EUVmicrolithography can offer one or more advantages corresponding to thosestated above with regard to the illumination system. Apart fromcorrecting the illumination-angle distribution, another function of anillumination system of such a projection exposure apparatus is,correspondingly, to monitor and correct the uniformity particularly inthe image plane of the projection optics. During the projectionillumination, this can guarantee an illumination as homogeneous aspossible of a photo-sensitive layer on the substrate to be exposed via adefault radiation energy or intensity, respectively, thus ensuring thatstructures are transferred from the mask onto the substrate without anylosses.

In certain embodiments, a diaphragm device can include a plurality ofindividual diaphragm bodies which are, starting from the edge,insertable into the illuminated aperture of the field planeindependently of each other correspond to those of the diaphragm deviceof an illumination system described further above which is provided witha plurality of individual diaphragm bodies which, starting from theedge, are insertable into a illuminated aperture of the pupil planeindependently of each other.

Individual, pivotable diaphragm bodies with which a field-distributiondiaphragm device of a projection exposure apparatus of theaforementioned type may be equipped and which project from the edge intothe illuminated aperture of the field plane independently of each other,with each individual diaphragm body being provided with a surfaceelement which is pivotable about an axis having at least one componentof direction which runs parallel to the field plane so as to change thesize of an area shadowed by the individual diaphragm body, allow for afine adjustment of the distribution of energy or intensity,respectively, of the illumination light in the field plane. It isparticularly advantageous if the diaphragm bodies are both insertableand pivotable.

In certain embodiments, an individual diaphragm body can provideadvantages corresponding to those of the individual diaphragm bodydescribed above, the individual diaphragm body having an edge contourthat leads in the direction of insertion and is adapted to anillumination substructure of the pupil plane to be shadowed.

Individual diaphragm bodies of a projection exposure apparatus of theaforementioned type the shape of which may be adapted to the at leastpartial shadowing of particular individual field facets of the fieldfacet mirror allow for a particularly fine adjustment of thedistribution of energy or intensity, respectively, of the illuminationlight in the field plane.

An insertion and pivot drive of a projection exposure apparatus of theaforementioned type may cooperate with an individual diaphragm body, andthus may include a guide unit for guiding the insertion movement along aguide axis, a pivot drive motor for pivoting the individual diaphragmbody about the guide axis, and a linear motor for moving the individualdiaphragm body along the guide axis, also includes decoupled drives forthe degrees of freedom insertion and pivoting.

EUV radiation absorbed by the diaphragm bodies and converted into heatcan be dissipated efficiently via a cooling body to which an theindividual diaphragm body of a projection exposure apparatus of theafore-mentioned type may be coupled, with the coupling advantageouslybeing obtained via a flexible copper line.

In some embodiments, a method can offer advantages that correspond tothe advantages of the projection exposure apparatus according to thedisclosure. Methods for correcting an illumination parameter in aprojection exposure apparatus for the EUV microlithography can allow formonitoring and correction of both ellipticity and telecentricity.

In certain embodiments, the methods can minimize the uniformity error ofthe field-plane intensity distribution in the projection exposureapparatus, and can allow to simultaneously monitor and correct theparameters controlling the illumination-angle distribution and theuniformity.

In some embodiments, the methods can be used to produce amicrostructured component. In such embodiments, the correctableillumination parameters can enable a relatively constant, highstructural resolution to be obtained over a long period of time.

A microstructured component according to at least one of the twoaforementioned methods has corresponding advantages.

In the following, exemplified embodiments of the disclosure will beexplained in more detail, taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic meridional section through a projectionexposure apparatus for EUV projection microlithography.

FIG. 2 shows, in a representation similar to FIG. 1, an enlargedellipticity sensor of the projection exposure apparatus as an example ofan illumination-angle sensor element.

FIG. 3 shows an even larger view of a sensor unit of the ellipticitysensor of FIG. 2.

FIG. 4 shows a schematic view of an octant distribution of a pupil planeof the projection exposure apparatus of FIG. 1.

FIG. 5 shows a pupil facet mirror of the projection exposure apparatusof FIG. 1 equipped with a movable illumination-angle diaphragm device.

FIG. 6 shows an enlarged individual diaphragm body of the diaphragmdevice of FIG. 5 equipped with an insertion drive.

FIG. 7 shows the pupil facet mirror of an illumination.

FIG. 8 shows a field facet mirror of the projection exposure apparatusof FIG. 1 equipped with a field-distribution diaphragm device.

FIG. 9 shows a scan-integrated field cycle of the uniformity in anobject plane of the projection exposure apparatus of an illuminationsystem for EUV microlithography.

FIG. 10 shows a detailed view of an individual diaphragm body of anotherembodiment of a field-distribution diaphragm device.

FIG. 11 shows a sectional view of another field facet mirror equippedwith a plurality of individual diaphragm bodies of FIG. 10.

DETAILED DESCRIPTION

FIG. 1 shows a schematic meridional section of a projection exposureapparatus 1 for the microlithography. An illumination system 2 of theprojection exposure apparatus 1 is provided with a radiation source 3and an illumination optics 4 for illuminating an object field in anobject plane 5. The radiation source 3 is an EUV source providing anemission wavelength of between 10 nm and 30 nm. A reticle 6 disposed inthe object field is exposed to illumination. A projection optics 7 isused for imaging the object field into an image field in an image plane8. A structure on the reticle is imaged onto a photo-sensitive layer ofa wafer 9 disposed in the area of the image field in the image plane 8.

For easier representation, FIG. 1 is provided with a Cartesiancoordinate system. The x-direction extends to the right in FIG. 1. They-direction extends vertically into the drawing plane in FIG. 1. Thez-direction extends upwards in FIG. 1. The displayed EUV radiation 10hits the object plane 5 at x=0.

The projection exposure apparatus 1 is configured as a scanner. Duringthe operation of the projection exposure apparatus 1, both the reticle 6and the wafer 9 are scanned synchronously in the y-direction.

EUV radiation 10, which is emitted by the radiation source 3, isinitially collimated by a collector 11. The collector 11 is configuredas a nested collector mirror equipped with a plurality of mirror shellsproviding for a grazing reflection of the EUV radiation 10 (grazingincidence). The individual shells of the collector 11 are held in placevia spokes which are disposed in the light path of the EUV radiation 10.Other configurations of the collector 11 are also conceivable.

Upon leaving the collector 11, the EUV radiation 10 propagates throughan intermediate focal plane 12 before hitting a field facet mirror 13.

FIG. 8 shows an enlarged plan view of the field facet mirror 13. Thisfield facet mirror 13 is equipped with a plurality of field facet groups14 arranged in columns and rows, the field facet groups 14 in turn beingcomposed of a plurality of curved individual facets 15. Straight, i.e.non-curved, individual facets are also conceivable, as will be describedin the following. The field facet mirror 13 is composed of severaldifferent types of field facet groups 14 which are equipped with adifferent number of individual facets 15. The field facet group 14 shownin the bottom left column of FIG. 8, for example, is subdivided into 10individual facets 15. Other field facet groups 12 may also include asmaller number of individual facets 15. The individual field facets 15of the field facet mirror 13 are arranged in the shape of the objectfield to be illuminated. Such field facet arrangements are for exampleknown from U.S. Pat. No. 6,452,661 and U.S. Pat. No. 6,195,201.

A field-distribution diaphragm device 16 adjoining the reflectingsurface of the field facet mirror 13 in the beam path of the EUVradiation 10 is only indicated in FIG. 1 and will be described in moredetail in the following.

The EUV radiation 10 reflected by the field facet mirror 13 is composedof a plurality of partial radiation beams, with each partial beam beingreflected by a particular individual facet 15. Each partial bundle hitsan associated individual facet (cp. FIG. 5) of a pupil facet mirror 18.The individual pupil facets 17 are round and hexagonal close packed. Thefield facet mirror 13 is used to generate secondary light sources at thesite of the individual facets 17 of the pupil facet mirror 18. The pupilfacet mirror 18 is disposed in a plane of the illumination optics 4which coincides with or is optically conjugated to a pupil plane of theprojection optics 7. An illumination-angle diaphragm device 19, whichwill be described in more detail in the following, is disposed adjacentto the reflecting surface of the pupil facet mirror 18 in the beam pathof the EUV radiation 10.

The individual field facets 15 of the field facet mirror 13 are imagedinto the object plane via the pupil facet mirror 18 and a transmissionoptics 20. The trans-mission optics 20 is provided with three reflectingmirrors 21, 22 and 23 which are disposed downstream of the pupil facetmirror 18.

The entire illumination optics 4, i.e. the field facet mirror 13, thepupil facet mirror 18 and the three mirrors 21 to 23 of the transmissionoptics 20 are held in place on a common, rigid support frame in a way asto keep thermal drifts of the positions of the reflecting surfaces ofthese components to a minimum during the operation of the projectionexposure apparatus 1. Due to the spatial conditions, it is generallyimpossible to attach the radiation source 3 and the collector 11directly to the support frame 24.

Serving as an example of an illumination-angle sensor element, anellipticity sensor 25 is disposed in the beam path between the lastmirror 23 of the transmission optics 20 and the object plane 5 fordetermining an actual illumination-angle distribution of the projectionexposure apparatus 1 in a field plane of the illumination optics 4.

FIGS. 2 and 3 show details of the ellipticity sensor 25. Thisellipticity sensor 25 includes a total of two sensor units 26 which areshown in FIGS. 1 and 2. FIG. 3 shows a detailed view of one of thesensor units 26. Alternative versions of the ellipticity sensor may alsoinclude more than two sensor units, e.g. four or eight sensor units.More than two sensor units may in particular be used if the measurablequantity referred to as ellipticity, which will be described in thefollowing, is to be determined in more detail for determiningscan-integrated values.

At the site of the ellipticity sensor 25, the cross-section of the EUVradiation 10 to which the object field is exposed has the shape of anarc. The two sensor units 26 are disposed at the edge positions of theillumination light, i.e. the EUV radiation 10, which are determined bythe two ends of the arc-shaped cross-section, the sensor units 26detecting the EUV radiation 10 impinging upon the edge positions, asshown in FIG. 2. The part of the EUV radiation 10 between these edgepositions, which is by far the major part of the EUV radiation, passesthrough the ellipticity sensor 25 without being affected or attenuated.The EUV radiation 10 detected at the edge positions is in the followingalso referred to as detection radiation 10.

Due to the identical design of the two sensor units 26, it suffices inthe following to describe one of the two sensor units 26 of theellipticity sensor 25. First of all, the sensor unit 26 includes adeflection element 27 in the shape of a deflection mirror for deflectinga detection beam path 28 by 90°, i.e. away from a main beam direction 29of the EUV radiation 10. The detection radiation 10 is subsequentlyguided through an apertured diaphragm 30 in a housing 31 of the sensorunit 26. The apertured diaphragm 30 has a round shape, with a diameterof between 100 and 300 μm. The apertured diaphragm 30 is disposed in adiaphragm plane 32 coinciding with a field plane or a plane of theprojection optics 7 which is conjugated thereto. A scintillator plate 33is the first element to be disposed downstream of the apertureddiaphragm 30 in the housing 31. The scintillator plate 33 converts theEUV radiation 10 into detection radiation of a wavelength which isdetectable by a spatial detector element 34 in the shape of a CCD arraydisposed downstream of the scintillator plate 33.

As indicated in FIG. 3, the detector element 34 detects an intensitydistribution 35 which corresponds to an illumination-angle distributionat the site of the apertured diaphragm 30. Since the apertured diaphragmis disposed in a field plane or intermediate field plane, respectively,of the projection optics 7, the intensity distribution 35 serves as ameasure for the illumination-angle distribution seen by an object pointin the object field, with the object point being exposed to the EUVradiation 10.

The intensity of the detection radiation, which is obtained from theincident EUV radiation 10 via the scintillator plate 33, depends on theangle of incidence of the EUV radiation 10 when hitting the scintillatorplate 33. If the EUV radiation 10 hits the scintillator plate 33 at aparticular angle of incidence, the intensity of the detection radiationis maximized. For example, the scintillator plate 33 may be designed ina way that EUV radiation 10 hitting the scintillator plate 33 in avertical direction is converted with maximum efficiency, the efficiencymonotonically decreasing if the angle of incidence of the incident EUVradiation 10 increases. This dependence, which is also referred to asresponse function of the scintillator plate 33, can be determinedexactly within the scope of a calibration measurement. This angledependence of the detection radiation generated in the scintillatorplate 33 can be determined from the signal detected by the CCD array viathis default calibration function.

Apart from the detection of illumination angles, another function of thetwo spatial detector elements 34 of the sensor units 26 is to determinethe integral of the EUV radiation 10 arriving from all detectedillumination angles, or of the radiation converted by the scintillatorplate 33, respectively. This integral is a measure for the total energyor intensity, respectively, which is provided by the illumination system2.

The ellipticity sensor 25 allows to measure the illumination-angledistribution during the operation of the projection exposure apparatus1. An alternative ellipticity sensor may serve to detect theillumination-angle distribution over the entire field plane. Thisalternative ellipticity sensor either allows for an output coupler to beintroduced in the beam path of the EUV radiation 10, thus ensuring thatthe entire EUV radiation 10 is transferred to an illumination-angledetection system, or for decoupling a detection beam along the entirecross-section of the EUV radiation 10 via a beam splitter, with thelargest part of the EUV radiation, in the shape of effective radiation,not being supplied to the ellipticity sensor but to the projectionsystem. Measurement via the ellipticity sensor 25 can be performedduring the replacement of a wafer.

The ellipticity, which is measurable via the ellipticity sensor 25, is ameasure for determining the quality of illumination of the object fieldin the object plane 5. In this respect, the determination of theellipticity helps to obtain exact information with regard to thedistribution of energy or intensity, respectively, over the pupil facetmirror 18. In order to do so, the distribution of intensity 35—and thusthe pupil facet mirror 18—is subdivided into eight octants which arenumbered in an anticlockwise direction from O₁ to O₈, as it is common inmathematics. The contribution of energy or intensity, respectively,delivered by the individual pupil facets 17 or sections thereof,respectively, in the octants O₁ to O₈ for illuminating a field point isin the following referred to as energy or intensity contribution,respectively, I₁ to I₈.

The following quantity is generally referred to as −45°/45°-ellipticity:

$E_{{- 45}/45} = \frac{I_{1} + I_{2} + I_{5} + I_{6}}{I_{3} + I_{4} + I_{7} + I_{8}}$

The following quantity is referred to as 0°/90°-ellipticity:

$E_{0/90} = \frac{I_{1} + I_{8} + I_{4} + I_{5}}{I_{2} + I_{3} + I_{6} + I_{7}}$

Since the ellipticity sensor is positioned at an angle of 22.5° withregard to the normal case, the ellipticities obtained via the aboveformula do not apply to the angles 0°/90° and −45°/45° but to22.5°/112.5° and −22.5°/67.5°. To simplify matters, however, thedesignations −45°/45°- and 0°/90°-ellipticity are retained in thisdocument.

The determined ellipticity is generally a scan-integrated one, with theellipticity value being obtained by integration over y, i.e. via thescanning process, at a particular x-value of the object field.

In practice, the intensity or energy, respectively, of the EUV radiation10 the field facet mirror 13 is exposed to is not constant over theentire surface of the field facet mirror 13. In practical operation, thedistribution of intensity or energy, respectively, over the surface ofthe field facet mirror 14 differs from the ideal uniform distribution.This may have several causes.

On the one hand, the adjustment of the radiation source 3 with respectto the collector 11, or the adjustment of the collector 11 with respectto the illumination optics 4, respectively, may be imperfect or subjectto thermal drifts. Such drifts may occur between the components on thesupport frame 24 and the other components of the illumination system 2.Other reasons causing the illumination of the field facet mirror 13 todiffer from the ideal case may be due to the extended shape of theradiation source 3. When using a plasma source as radiation source 3,electrode abrasion or plasma migration may cause the illuminationdistribution to drift on the field facet mirror 13 at a time constant inthe range of minutes to hours. A drift may also be caused by longerperiods of operation resulting in a deformation of the collector 11, orby contamination resulting in a change of its reflection properties. Anot perfectly uniform illumination of the field facet mirror 13 may forexample be caused due to the design of the collector 11 being providedwith support spokes between the individual collector shells. Thesespokes block a certain amount of the EUV radiation which is then nolonger available for the illumination of the field facet mirror 13.

Even a field facet mirror 13 which is illuminated in a perfectlyhomogeneous manner does not guarantee a correspondingly perfectillumination of the object field. In addition, the illumination of theobject field may be affected due to the design of the illuminationoptics 4 and due to inhomogeneous reflection losses at the severaldeflection elements.

In the ideal case, the individual pupil facets 17 are exposed to thepartial radiation beams emitted by the individual field facets in a waythat a centroid of energy or intensity, respectively, of the exposure isin the exact centre of the pupil facet mirror 18 and that random surfacesections, in particular random sections of the pupil facet mirror 18,are exposed to the same amount of energy or intensity, respectively.

The position of the centroid of energy or intensity, respectively, ismeasured in terms of telecentricity.

A centroid beam of a light bundle associated with each field point isdefined in each field point of the illuminated object field. Theenergy-weighted direction of the centroid beam corresponds to that ofthe light bundle emitted by this field point. In the ideal case, thecentroid beam of each field point runs parallel to the main beam emittedby the illumination optics 4 or the projection optics 7, respectively.

The direction of the main beam {right arrow over (s)}₀ (x,y) is knownfrom the design data of the illumination optics 4 or the projectionoptics 7, respectively. The main beam is defined at a field point by theconnection line between the field point and the centre of the entrancepupil of the projection optics 7. The direction of the centroid beam ata field point x, y in the object field in the object plane is obtainedas follows:

${\overset{\rightarrow}{s}\left( {x,y} \right)} = {\frac{1}{\overset{\sim}{E}\left( {x,y} \right)}{\int\ {{u}{{v\begin{pmatrix}u \\v\end{pmatrix}}}{{E\left( {u,v,x,y} \right)}.}}}}$

E (u, v, x, y) refers to the energy distribution for the field point x,y as a function of the pupil coordinates u, v, i.e. as a function of theillumination angle seen by the corresponding field point x, y.

In this respect, {tilde over (E)}(x, y)=∫dudvE(u, v, x, y) refers to thetotal energy the point x, y is exposed to.

The radiation of a partial radiation beam is seen by a, for example,central object field point x₀, y₀ from directions u, v which are definedby the positions of the corresponding individual pupil facets 17.

At this illumination, the centroid beam is not directed along the mainbeam unless the different energies or intensities, respectively,associated with the individual pupil facets 17 combine to form acentroid beam direction which is integrated over all individual pupilfacets 17 and runs parallel to the main beam direction. This happensonly in the ideal case. In practice, there is a difference between thecentroid beam direction {right arrow over (s)}(x, y) and the main beamdirection {right arrow over (s)}₀(x, y) which is referred to astelecentricity error {right arrow over (t)}(x, y):

{right arrow over (t)}(x,y)={right arrow over (s)}(x,y)−{right arrowover (s)} ₀(x,y)

During the practical operation of the projection exposure apparatus 1,it is not the static telecentricity error in a particular object fieldthat should be corrected but the scan-integrated telecentricity error atx=x₀ which is obtained as follows:

${\overset{\rightarrow}{T}\left( x_{0} \right)} = {\frac{\int\ {{y}{\overset{\sim}{E}\left( {x_{0},y} \right)}{\overset{\rightarrow}{t}\left( {x_{0},y} \right)}}}{\int\ {{y}{\overset{\sim}{E}\left( {x_{0},y} \right)}}}.}$

Accordingly, the telecentricity error is corrected which is seenenergy-weighted and integrated by a point on a given field height (x,e.g. x₀) moving through the object field in the object plane 5 during ascan.

The projection exposure apparatus 1 is equipped with theillumination-angle diaphragm device 19 for the corrective adjustment ofboth ellipticity and telecentricity. The embodiment of thisillumination-angle diaphragm device 19 shown in FIG. 5 includes eightindividual diaphragm bodies 36 to 43 the numbering of which starts withthe individual diaphragm body 36 disposed at the 3 o'clock position ofthe pupil facet mirror 18 and continues in an anticlockwise direction.The number of the individual diaphragm bodies 36 to 43 thus equals thenumber of the octants I₁ to O₈. Starting from the edge, the individualdiaphragm bodies are radially insertable into the illuminated apertureof the pupil facet mirror 18 independently of each other. The individualdiaphragm bodies 36 to 43 are arranged around the pupil facet mirror 18in a uniformly distributed manner so that the directions of insertion ofadjacent individual diaphragm bodies 36 to 43 have an angle of 45° withrespect to each other.

The individual diaphragm bodies 36, 38, 40 and 42 have a leading edgecontour 44, 45 which is adapted to the illumination substructure of thepupil plane to be shadowed, i.e. to the hexagonal closest packing of theindividual pupil facets 17. The individual diaphragm bodies 36, 40 whichare disposed in the 3 and 9 o'clock positions in FIG. 5 have fouradjacent circular diaphragm sections 46 each, with the size and shapethereof equaling the size and shape of one individual pupil facet 17each. The edge contour 44 is formed by the combined diaphragm sections46. The edge contours 45 of the individual diaphragm bodies 38, 42 whichare disposed in the 12 or 6 o'clock positions, respectively, in FIG. 5are composed of four diaphragm sections 46 each which correspond to theindividual pupil facets 17. Due to the hexagonal close packedarrangement of the individual pupil facets 17, the diaphragm sections 46of the edge contours 45 are not disposed next to each other but in pairsthe two partners of which being offset from each other by half adiaphragm section.

The other individual diaphragm bodies 37, 39, 41 and 43 of theillumination-angle diaphragm device 19 are each of rectangular shape,the edge contours thereof thus not being adapted to the substructure ofthe pupil plane illumination. The individual diaphragm bodies 37, 39, 41and 43 cover a surface corresponding to several adjacent individualpupil facets.

A default amount of intensity of the EUV radiation 10 can be blocked inone of the octants O₁ to O₈ by inserting the individual diaphragm bodies36 to 43 into the aperture of the pupil facet mirror 18.Correspondingly, ellipticity on the one hand and telecentricity on theother hand can be altered by inserting particular individual diaphragmbodies 36 to 43.

The following is a description, via the example of the individualdiaphragm body 36 (cp. FIG. 6), of the design of an insertion drivecooperating with each of the individual diaphragm bodies 36 to 43. Theinsertion drive 47 includes a guide unit 49 guiding the insertionmovement in the direction of insertion 48. The guide unit 49 guides aguide body 50 in the shape of a guide rod which is connected to a basebody 51 of the individual diaphragm body 36. In the case of theindividual diaphragm body 36, it is the base body 51 which carries thefour diaphragm sections 46 of the edge contour 44.

The insertion drive 47 further includes a pivotable lever arm 52 whichis articulated with the guide body 50. The lever arm 52 is pivotallydrivable about a stationary pivot axis 53. In order to do so, the leverarm 52 cooperates with a pivot drive motor 54 of the insertion drive 47.The pivot drive motor 54 is configured as an electric motor. A portionof the lever arm 52 facing away from the guide body 50 forms a rotor 55of the pivot drive motor 54, the rotor 55 cooperating with a stator 56.

FIG. 7 shows an alternative version of an illumination-angle diaphragmdevice 19 including three individual diaphragm bodies 57, 58, 59 thedesign of which equals that of the individual diaphragm body 36 in FIG.6. In the embodiment of the illumination-angle diaphragm device in FIG.7, the individual diaphragm bodies 57 to 59 are disposed at the site ofthe individual diaphragm bodies 36 to 38 in the embodiment of FIG. 5.The other five individual diaphragm bodies are omitted in therepresentation of FIG. 7. Along with the detailed design of theindividual diaphragm bodies 57 to 59, FIG. 7 also illustrates thecompact arrangement of the insertion drives 47 around the pupil facetmirror 18.

FIG. 8 shows a detailed view of the field-distribution diaphragm device16 together with the field facet mirror 13.

The field-distribution diaphragm device 16 allows to adjust theuniformity, i.e. the homogeneity of the scanning energy (SE) over thefield height x, i.e. the energy or intensity, respectively, seen by afield point, scanned over the object field, which is integrated over alldirections.

In general, the following applies:

SE(x)=∫E(x,y)dy, with

E being the intensity distribution in the x-y field plane as a functionof x and y. In order to achieve a uniform, i.e. homogeneous illuminationand other characteristic quantities of the illumination system, such asellipticity and telecentricity which are also functions of the fieldheight x, it is advantageous if these quantities have substantiallyconstant values with only minor deviations substantially over the entirefield height x.

The uniformity of the scanning energy in the field plane is measured interms of the variation of the scanning energy over the field height. Theuniformity is thus described in percent via the following equation withregard to the uniformity error:

${\Delta \; {SE}} = {\frac{{SE}_{\max} - {SE}_{\min}}{{SE}_{\max} + {SE}_{\min}} \times {100\lbrack\%\rbrack}}$

In this equation, the following applies:

ΔSE: the uniformity error or the variation of the scanning energy,respectively, in %;SE_(max): maximum value of the scanning energy;SE_(min): minimum value of the scanning energy.

The field-distribution diaphragm device 16 allows for an adjustable,partial attenuation of illumination light of the radiation source 3 inthe area of a field plane of the illumination optics 4. To this end, thefield-distribution diaphragm device 16 is provided with a plurality ofindividual diaphragm bodies 60, with the exemplified embodiment of FIG.8 including a total of eight individual diaphragm bodies 60. Startingfrom the edge of the field facet mirror 13, these individual diaphragmbodies 60 are radially insertable into the illuminated aperture, i.e.into the illuminated aperture of the field plane, independently of eachother. The eight individual diaphragm bodies 60 are uniformlydistributed around the circumference of the field facet mirror 13, withfour of the eight individual diaphragm bodies 60 being disposed in the 3o'clock, 6 o'clock, 9 o'clock and 12 o'clock positions and each of theother four individual diaphragm bodies 60 being disposed between two ofthese first four individual diaphragm bodies 60. Apart from the twoindividual diaphragm bodies 60 which are disposed in the 6 and 12o'clock positions and whose edge contours 61, 62 are adapted to thearcuate shape of the individual facets 15, the shape of all individualdiaphragm bodies 60 corresponds to the compressed hexagonal shape of adiaphragm section 64 leading in a direction of insertion 63.

The diaphragm sections with the edge contours 61, 62 as well as thediaphragm sections 64 are surface elements which may cover approximatelyhalf of a field facet group 14. These surface elements are not onlyinsertable along the radial directions of insertion 63 but alsopivotable about these directions of insertion 63, as can be seen fromthe exemplified individual diaphragm bodies 60 shown in the 3 o'clock, 6o'clock, 9 o'clock and 12 o'clock positions in FIG. 8. The size of thesurface elements of the individual diaphragm bodies 60 is adapted to theshape of the individual field facets 15 and/or to an illuminationsubstructure of the field facet mirror 13. For example, a dimension ofthe diaphragm sections 64 corresponds to the dimension of the shells orof the spokes of the collector. This way, the individual diaphragmbodies 60 directly affect the scan-integrated uniformity. The uniformityis measurable via a uniformity sensor 64 a which may replace the wafer 9in the image plane 8 and is schematically indicated below the wafer 9 inFIG. 1. Likewise, the uniformity sensor 64 a is a CCD array alsoequipped with a scintillator plate. The uniformity sensor 64 a is afield-distribution sensor element in the image plane 8.

FIG. 9 shows a schematic example of a measured uniformity Uscan-integrated over the field coordinate x. The scan-integratedintensity I is shown. The representation shows several characteristicpeaks P. The width of these peaks corresponds to the width of thecollector shells of the collector 11 which are imaged on the field facetmirror 13. The distribution of the uniformity according to FIG. 9 can becorrected by inserting the individual diaphragm bodies 60. In order todo so, the individual diaphragm bodies 60 are disposed at thosex-coordinates where the peaks P of the uniformity occur. This way, thepeaks P are reduced, with the correction thus resulting in, for example,the dashed uniformity U′ the homogeneity of which is considerablygreater than that of the continuous uniformity U.

When correcting the uniformity, certain individual field facets 15 arepartially covered. This entails, of course, a corresponding attenuationof the illumination of the individual pupil facets 17 associated withthese individual field facets. Since, however, a majority ofconfigurations of the individual diaphragm bodies 60 result in the samecorrection of uniformity, that particular configuration of individualdiaphragm bodies 60 may be selected in which both ellipticity andtelecentricity correspond most closely to an ideal case. If necessary,adjustment and correction of uniformity on the one hand as well asellipticity and telecentricity on the other hand may be performed in aniterative process.

FIGS. 10 and 11 show a detailed view of another embodiment of afield-distribution diaphragm device. The shape of the individualdiaphragm bodies 65 incorporated therein are adapted to individual fieldfacets 66 of a field facet group 67, i.e. to an illuminationsubstructure of the field plane to be shadowed, of another embodiment ofa field facet mirror. The individual field facets 66 of this otherembodiment of the field facet mirror, which may replace the field facetmirror 13 in the projection exposure apparatus 1 of FIG. 1, are notcurved but have an elongated rectangular shape, i.e. they are straight.A width B of the individual diaphragm bodies 65 equals the width of thenarrow sides of the individual field facets 66. A length L of theindividual diaphragm bodies 65 approximately equals half the length ofthe long sides of the individual field facets 66.

The individual diaphragm bodies 65 are movable via an insertion andpivot drive 68 schematically represented in FIG. 10. This allows for theindividual diaphragm bodies 65 to be moved along a direction ofinsertion 69, i.e. along a guide rod 70 which carries the individualdiaphragm body 65, and to be pivoted about the direction of insertion69, i.e. about the guide rod 70. The insertion and pivot drive 68includes a guide unit 71 for guiding the guide rod 70 along thedirection of insertion 69. A linear/pivot drive motor 72 serves, on theone hand, to pivot the individual diaphragm body 65 about the directionof insertion 69 and, on the other hand, to move the individual diaphragmbody 65 along the direction of insertion 69.

The individual diaphragm body 65 is coupled to a cooling body 74 via theguide rod 70 and a flexible copper line 73. Corresponding to theindividual diaphragm body 65, the individual diaphragm bodies 36 to 43,57 to 59 or 60 may also be cooled.

FIG. 1 schematically represents other components for measurement,control or calculation, respectively, which may serve to automaticallycorrect both ellipticity and telecentricity as well as the uniformity ofthe projection exposure apparatus 1.

The ellipticity sensor 25 is connected to an evaluation device 76 via asignal connection 75. The evaluation device 76 is connected to theuniformity sensor 64 a via a signal line 77. The evaluation device 76thus serves both as an illumination-angle evaluation device as well as afield-distribution evaluation device. A nominal illumination-angledistribution is stored in the evaluation device 76. This nominalillumination-angle distribution may be the result of a calibrationmeasurement of the illumination-angle distribution. Moreover, a nominalintensity distribution is also stored in the evaluation device. Thisnominal intensity distribution may be the result of a calibrationuniformity measurement. A signal connection is provided between theevaluation device 76 and a control device 79 via a signal line 78, thecontrol device 79 serving both as an illumination-angle control deviceas well as a field-distribution control device. A signal connection isprovided between the control device 79 and the illumination-anglediaphragm device 19 via a signal line 80 and between the control device79 and the field-distribution diaphragm device 16 via a signal line 81.

For correcting the ellipticity of the illumination-angle distribution inthe projection exposure apparatus 1, the actual ellipticity is, in afirst step, measured via the illumination-angle sensor element 25. In asecond step, it is determined which of the illumination sectors, i.e.which of the octants O₁ to O₈, is to be used for correcting theellipticity via the illumination-angle diaphragm device. This happensvia the evaluation device 76 which determines the weighting between theoctants O₁ to O₈ and, with regard to the nominal average illuminationdistribution stored in the evaluation device 76, defines the octant O₁to O₈ the shadowing of which is to be increased, for example.Subsequently, the selected illumination sector and the amount ofshadowing to be selected are transmitted from the evaluation device 76to the control device 79 via the signal line 78. The control device 79then generates an illumination-angle control signal for actuating theparticular individual diaphragm body 36 to 43 in the embodiment of FIG.5, or the corresponding diaphragm body of the embodiment of FIG. 7,respectively, which is associated with the selected illumination sector.This selected individual diaphragm body, e.g. the individual diaphragmbody 36 in the embodiment of FIG. 5, is then moved into this section sothat illumination light of the radiation source 3 is partiallyattenuated in the area of the illumination sector to be corrected, forexample the illumination sector O₁.

Corresponding to the above description in terms of ellipticitycorrection, it is also possible to correct the telecentricity of theillumination.

A first step for correcting the uniformity of the field-plane intensitydistribution in the projection exposure apparatus 1 is to measure anactual uniformity via the uniformity sensor 64 a. In a second step, theevaluation device 76 is used to determine, with regard to the nominalintensity distribution stored therein, a field section, i.e. an areabetween two x-values of the field coordinate, which is to be corrected.This field section to be corrected and the amount of correction to begenerated are then transmitted from the evaluation device 76 to thecontrol device 79. The control device 79 then generates afield-distribution control signal for actuating at least that diaphragmbody 60 or 65, respectively, which is associated with the field sectionto be corrected. Subsequently, the respective diaphragm body 60, 65 isinserted or pivoted, respectively, so as to partially attenuate thelight of the radiation source 3 in the area of the at least one fieldsection to be corrected, thus obtaining the desired correction ofuniformity.

Unwanted interactions between the correction of ellipticity andtelecentricity on the one hand and the correction of uniformity on theother hand may be reduced to a minimum by iteratively performing thecorrection methods.

The direction of insertion runs parallel to the reflection plane of thefield facet mirror 13, i.e. substantially parallel to a field plane inwhich the field facet mirror 13 is disposed. It generally suffices if atleast one direction component of the direction of insertion 63 runsparallel to the field plane. Correspondingly, the same applies to thedirections of insertion 48 (cp. FIG. 6) and 69 (cp. FIG. 10).

1. An illumination system, comprising: an illumination optics designedso that, during use, the illumination optics can guide light from aradiation source to an object field in an object plane; anillumination-angle sensor element designed so that, during use, theillumination-angle sensor can determine an actual illumination-angledistribution of a projection exposure apparatus in a field plane of theillumination optics; an illumination-angle evaluation device comprisinga signal connection to the illumination-angle sensor element, theillumination-angle evaluation device being designed so that, during use,a nominal illumination-angle distribution is stored via theillumination-angle evaluation device; an illumination-angle controldevice comprising a signal connection to the illumination-angleevaluation device, the illumination-angle control device being designedso that, during use, the illumination-angle control device generates anillumination-angle control signal depending on a difference between theactual illumination-angle distribution and the nominalillumination-angle distribution; and at least one movableillumination-angle diaphragm device comprising a signal connection tothe illumination-angle control device, the at least one movableillumination-angle diaphragm device being configured so that, duringuse, the at least one illumination-angle diaphragm device can move atleast one illumination-angle diaphragm body to achieve an adjustable,partial attenuation of the light in the area of a pupil plane of theillumination optics, wherein the illumination system is an EUVmicrolithography illumination system.
 2. An illumination systemaccording to claim 1 wherein, during use, the illumination-angle sensorelement detects the illumination-angle distribution over the entirefield plane.
 3. An illumination system according to claim 1 wherein,during use, the illumination-angle sensor element detects theillumination-angle distribution in at least one field position by usinglight at the edge of the cross-section of the light.
 4. An illuminationsystem according to claim 3 wherein the illumination-angle sensorelement comprises at least one deflection element configured so that,during use, the at least one deflection element can deflect a detectionbeam path of the illumination-angle sensor element away from a main beamdirection of the illumination light.
 5. An illumination system accordingto claim 3 wherein, during use, the illumination-angle sensor elementdetects the illumination-angle distribution by using light at four edgepositions of the beam cross-section of the light, the edge positionsdefining the corners of a rectangle.
 6. An illumination system accordingto claim 5 wherein the illumination-angle sensor element is designed sothat, during use, the illumination-angle sensor element can detect theillumination angles and, at the same time, an integral of the lightarriving from all detected illumination angles.
 7. An illuminationsystem according to claim 6 wherein the illumination-angle sensorelement comprises: an apertured diaphragm disposed so that, during use,the apertured diaphragm is at a position in a field plane, or a plane ofthe illumination optics conjugated thereto, which may be exposed to thelight; a spatial detector element disposed so that, during use, thespatial detector element is downstream of the apertured diaphragm, andso that the spatial detector element can, during use, detect anintensity distribution which corresponds to the illumination-angledistribution at the site of the apertured diaphragm.
 8. An illuminationsystem according to claim 7 wherein the sptaital detector elementcomprises a CCD array.
 9. An illumination system according to claim 8wherein the CCD array comprises a conversion element configured so that,during use, the conversion element can convert the wavelength of thelight into a wavelength detectable by the CCD array.
 10. An illuminationsystem according to claim 9 wherein the illumination angle diaphragmdevice comprises a plurality of individual diaphragm bodies which areinsertable into an illuminated aperture of the pupil plane independentlyof each other.
 11. An illumination system according to claim 10comprising at least one individual diaphragm body having an edge contourwhich leads in the direction of insertion and is adapted to anillumination substructure of the pupil plane to be shadowed.
 12. Anillumination system according to claim 10 wherein the number of theindividual diaphragm bodies is adapted to the illumination parameters tobe corrected.
 13. An illumination system according to claim 12 furthercomprising an insertion drive designed to cooperate with an individualdiaphragm body, the insertion drive comprising: a guide unit configuredto be capable of guiding insertion movement; a pivotable lever armarticulated with a guide body which can be guided in the guide unit andfirmly connected to a base body of the individual diaphragm body; and adrive motor, the lever arm being capable of cooperating with the pivotdrive motor.
 14. An illumination system according to claim 13 whereinthe pivot drive motor is an electric motor, and a portion of the leverarm simultaneously forms a rotor of the electric motor.
 15. A projectionexposure apparatus, comprising: an illumination optics designed so that,during use, the illumination optics can guide light from a radiationsource to an object field in an object plane; a projection opticsdesigned so that, during use, the projection optics can image the objectfield into an image field in an image plane; a field-distribution sensorelement designed so that, during use, the field-distribution sensorelement can determine an actual intensity distribution of the projectionexposure apparatus in a field plane of the projection optics; afield-distribution evaluation device comprising a signal connection tothe field-distribution sensor element, the field-distribution evaluationdevice being designed so that, during use, a nominal distribution ofintensity over the field can be stored via the field-distributionevaluation device stored; a field-distribution control device comprisinga signal connection to the field-distribution evaluation device, thefield-distribution control device designed so that, during use, thefield-distribution control device generates a signal depending on thedifference between the actual intensity distribution and the nominalintensity distribution; and at least one movable field-distributiondiaphragm device comprising a signal connection to thefield-distribution control device, the at least one movablefield-distribution diaphragm device designed so that, during use,depending on the field-distribution control signal, at least one movablefield-distribution diaphragm device moves at least onefield-distribution diaphragm body to achieve an adjustable, partialattenuation of illumination light of the radiation source in the area ofa field plane of the illumination optics, wherein the projectionexposure apparatus is a projection exposure apparatus for EUVmicrolithography.
 16. A projection exposure apparatus according to claim15 wherein the field-distribution diaphragm device comprises a pluralityof individual diaphragm bodies which are insertable into the illuminatedaperture of the field plane independently of each other.
 17. Aprojection exposure apparatus according to claim 16 wherein thefield-distribution diaphragm device comprises a plurality of individualdiaphragm bodies which, during use, starting from the edge, project intothe illuminated aperture of the field plane independently of each other,with each individual diaphragm body including a surface element which ispivotable about an axis having at least one component of direction whichruns parallel to the field plane so as to change the size of an areashadowed by the individual diaphragm body.
 18. A projection exposureapparatus according to claim 17 wherein at least one individualdiaphragm body has an edge contour which is adapted to an illuminationsubstructure of the field plane to be shadowed.
 19. A projectionexposure apparatus according to claim 18 wherein individual diaphragmbodies have a shape which is adapted to the at least partial shadowingof particular individual field facets of the field facet mirror.
 20. Aprojection exposure apparatus according to claim 19 further comprisingan insertion and pivot drive designed so that, during use the insertionand pivot drive can cooperate with an individual diaphragm body, theinsertion and pivot drive comprise: a guide unit capable of guiding theinsertion movement along a guide axis; a pivot drive motor designed sothat, during use the pivot drive motor can pivot the individualdiaphragm body about the guide axis; and a linear motor designed sothat, during use, the linear motor can move the individual diaphragmbody along the guide axis.
 21. A projection exposure apparatus accordingto claim 20 wherein the individual diaphragm body is coupled to acooling body.
 22. A method, comprising: correcting an illuminationparameter of the EUV microlithography projection exposure apparatusaccording to claim
 15. 23. A method according to claim 22, comprising:measuring an actual ellipticity via the illumination-angle sensorelement to determine the actual illumination-angle distribution of theprojection exposure apparatus in a field plane of the illuminationoptics; determining, via the illumination-angle evaluation device, atleast one illumination sector to be corrected; generating anillumination-angle control signal via the illumination-angle controldevice to actuate at least that diaphragm body of the illumination-anglediaphragm device which is associated with the illumination sector; andpartially attenuating, via the actuated diaphragm body, illuminationlight of the radiation source in the area of the at least oneillumination sector to be corrected.
 24. A method according to claim 22,comprising: measuring an actual uniformity via the field-distributionsensor element; determining, via the field-distribution evaluationdevice, at least one field section to be corrected; generating afield-distribution control signal via the field-distribution controldevice to actuate at least that diaphragm body of the field-distributiondiaphragm device which is associated with the field section to becorrected; and partially attenuating, via the actuated diaphragm body,illumination light of the radiation source in the area of the at leastone field section to be corrected.
 25. A method, comprising: using aprojection exposure apparatus according to claim 15 to project at leastpart of a mask onto an area of a photo-sensitive material.
 26. Themethod of claim 25, wherein the method provides a microstructuredcomponent.